When you didn't wash your bits after sex or masturbation and the sperm has dried up and made a disgusting smelling cheese.
Bro 1: Hey bro imma take a leak
Bro 2: Yeah sure bro
*1 min later*
Bro 1: ey bro it be looking like a cheesy leak down there!
Bro 2: that's disgusting bro go wash yourself!